TDRSS lightcurve for Trigger=1350381

Notes:

GCN BAT Position Notice

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 17 Sep 25 06:27:55 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1350381,   Seg_Num: 0
GRB_RA:          291.378d {+19h 25m 31s} (J2000),
                 291.681d {+19h 26m 43s} (current),
                 290.788d {+19h 23m 09s} (1950)
GRB_DEC:         +11.113d {+11d 06' 48"} (J2000),
                 +11.166d {+11d 09' 57"} (current),
                 +11.013d {+11d 00' 47"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       464 [cnts]    Image_Peak=76 [image_cnts]
TRIGGER_DUR:     0.032 [sec] 
TRIGGER_INDEX:   10318     E_range: 25-100 keV
BKG_INTEN:       16200 [cnts]
BKG_TIME:        23251.65 SOD {06:27:31.65} UT
BKG_DUR:         8 [sec]
GRB_DATE:        20935 TJD;   260 DOY;   25/09/17
GRB_TIME:        23264.13 SOD {06:27:44.13} UT
GRB_PHI:         -11.70 [deg]
GRB_THETA:        43.82 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     44.81 [sigma]
IMAGE_SIGNIF:    9.69 [sigma]
MERIT_PARAMS:     +1  +0  +0  -5  +2  +0  +0  +1 +42  +0 
SUN_POSTN:       175.07d {+11h 40m 16s}   +2.13d {+02d 08' 04"}
SUN_DIST:        115.59 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
MOON_POSTN:      123.75d {+08h 15m 00s}  +23.87d {+23d 52' 16"}
MOON_DIST:       143.03 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:       46.70, -2.38 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      295.15, 32.70 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 202.06,-9.33 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(0.0<100sec) coincident with the FERMI_GBM event (trignum=779783269).

GCN BAT Lightcurve Notice

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 17 Sep 25 06:40:07 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1350381,   Seg_Num: 0
GRB_RA:          291.378d {+19h 25m 31s} (J2000),
                 291.681d {+19h 26m 43s} (current),
                 290.788d {+19h 23m 09s} (1950)
GRB_DEC:         +11.113d {+11d 06' 48"} (J2000),
                 +11.166d {+11d 09' 57"} (current),
                 +11.013d {+11d 00' 47"} (1950)
GRB_DATE:        20935 TJD;   260 DOY;   25/09/17
GRB_TIME:        23264.32 SOD {06:27:44.32} UT
TRIGGER_INDEX:   10318
GRB_PHI:         -11.70 [deg]
GRB_THETA:        43.82 [deg]
DELTA_TIME:      13.00 [sec]
TRIGGER_DUR:     0.032 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     44.81 [sigma]
IMAGE_SIGNIF:    9.69 [sigma]
LC_URL:          sw01350381000msb.lc

GCN template for BAT paragraph

  • Click here! 
    At 06:27:44 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 250917 ***A*** (trigger=1350381).  Swift slewed immediately to the burst.
The BAT on-board calculated location is 
RA, Dec 291.378, +11.113 which is 
   RA(J2000) = 19h 25m 31s
   Dec(J2000) = +11d 06' 48"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a [**double-peaked**]
structure with a duration of about TTT sec.  The peak count rate
was ~8101 counts/sec (15-350 keV), at ~0 sec after the trigger.
  • Test version of draft template

    Initial TDRSS lightcurve and spacecraft attitude plot

    TDRSS lightcurve from T0-30 to T0+50 (zoom in)

    TDRSS light curve from T0-1 to T0+2 (More zoom in)

    1.6s binned TDRSS light curve

    Tilan's background subtracted TDRSS light curves

    Extended TDRSS light curve and spacecraft attitude plot(s)

    Extended TDRSS lc No.1

    Extended TDRSS lc No.2

    TDRSS extended lightcurve from T0-1 to T0+2

    T50 and T90 calculation

    ******************************************
         battblocks v1.18
------------------------------------------
     Input Data: bat_raw_lc.fits
     Output GTI: bb.gti
 Events to Skip: 128     Changepoint log(prob) Prior: 6.000000
  Internal Tick: 1.000000e-04 s
  Lookback time: 0 s
 Bkg. Subtract?: yes (for fluence/T50/T90 calculations)
------------------------------------------
  Estimated T90 duration: 108.288 s +/- 87.2215 s
  Estimated T50 duration: 108.288 s +/- 88.341 s
  Estimated Peak Interval: MET   779783300.86399996 +/- 0.500000 s
  Estimated background rate 1:     3915.071 near MET 779783288.704000 s
  Estimated background rate 2:     4394.082 near MET 779783447.808000 s
  Estimated total duration: 108.288 s (for data selection)
       (from MET 779783300.608000 to MET 779783408.896000)
  Estimated total fluence: -528.712861 count
  Created GTI with 9 entries
------------------------------------------

    Search for this GRB position to the previously BAT detected GRB positions (search radius within 5 arcmin)

    bat_grb_pos_cat.sh 291.378 11.113 0.083
No match

    Search for this GRB position to the source locations in BAT transient monitor (search radius within 12 arcmin)

    python compare_catalog.py 291.378 11.113
No match

    Link to SIMBAD

  • Click here for the SIMBAD search!

    Frank's UVOT result

  • Click here!

    Frank's UVOT Blinking images

  • Click here!

    Elevation angle of GRB/Sun at the ground telescope locations

    GSFC, Greenbelt, Maryland
      TimeUT       Azimuth     Elevation
 Sun: 2025 9 17 6 200.711575  -46.911839
 Obj: 2025 9 17 6 90.926582  16.737042
  • the object visibility at GSFC, Greenbelt, Maryland 
     
MMT Observatory, Mt. Hopkins, Arizona
      TimeUT       Azimuth     Elevation
 Sun: 2025 9 17 6 146.932827  -51.231443
 Obj: 2025 9 17 6 72.701242  45.093156
  • the object visibility at MMT, Mt. Hopkins, Arizona 
     
Hale Telescope, Palomar Mountain, California
      TimeUT       Azimuth     Elevation
 Sun: 2025 9 17 6 140.175407  -46.894149
 Obj: 2025 9 17 6 65.872175  49.228080
  • the object visibility at Hale Telescope, Palomar Mt., California 
     
Mauna Kea, Hawaii
      TimeUT       Azimuth     Elevation
 Sun: 2025 9 17 6 101.317715  -23.034201
 Obj: 2025 9 17 6 352.154511  81.246324
  • the object visibility at Mauna Kea, Hawaii 
     
Siding Spring Obs., Australia
      TimeUT       Azimuth     Elevation
 Sun: 2025 9 17 6 108.642281  24.063481
 Obj: 2025 9 17 6 241.486580  21.065984
  • the object visibility at Siding Spring Obs., Australia 
     
Tokyo, Japan
      TimeUT       Azimuth     Elevation
 Sun: 2025 9 17 6 61.013497  38.349681
 Obj: 2025 9 17 6 269.972870  19.969091
  • the object visibility at Tokyo, Japan 
     
William Herschel Telescope, La Palma, Canary Islands, Spain
      TimeUT       Azimuth     Elevation
 Sun: 2025 9 17 6 259.721091  -13.816938
 Obj: 2025 9 17 6 127.067835  -31.996945
  • the object visibility at William Hershel Telescope, La Palma, Canary Islands, Spain 
     
Gemini South, Cerro Pachon, Chile
      TimeUT       Azimuth     Elevation
 Sun: 2025 9 17 6 322.446011  -56.103648
 Obj: 2025 9 17 6 103.014188  0.044470
  • the object visibility at Gemini South, Cerro Pachon, Chile 
     
 
 
The data/results are in /local/data/bat1/prebascript/trigger1350381/tdrss_ql/
 
bat_raw_lc.fits  : TDRSS FITS light curve from GCN
gcn_position.txt : GCN BAT position notice
ratelc_tdrss.qdp : QDP file of the TDRSS light curve
tdrss_lc.gif     : GIF TDRSS light curve
sc_att.qdp       : QDP file of the spacecraft attitude
sc_att.gif       : GIF spacecraft attitude
bb.gti           : Bayesian block GTI file (battblocks)
dur.gti          : Duration GTI file (battblocks)
battblocks.log   : Output log of battblocks
 


    Plot creation:
Wed Sep 17 02:41:02 EDT 2025